Commit b8baac3b authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso
Browse files

netfilter: flowtable: teardown flow if cached mtu is stale 



Tear down the flow entry in the unlikely case that the interface mtu
changes, this gives the flow a chance to refresh the cached mtu,
otherwise such refresh does not occur until flow entry expires.

Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 03428ca5

net/netfilter/nf_flow_table_ip.c

+6 −2
Original line number Diff line number Diff line
@@ -377,8 +377,10 @@ static int nf_flow_offload_forward(struct nf_flowtable_ctx *ctx, 
	flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);



	mtu = flow->tuplehash[dir].tuple.mtu + ctx->offset;

	if (unlikely(nf_flow_exceeds_mtu(skb, mtu)))

	if (unlikely(nf_flow_exceeds_mtu(skb, mtu))) {

		flow_offload_teardown(flow);

		return 0;

	}



	iph = (struct iphdr *)(skb_network_header(skb) + ctx->offset);

	thoff = (iph->ihl * 4) + ctx->offset;
@@ -656,8 +658,10 @@ static int nf_flow_offload_ipv6_forward(struct nf_flowtable_ctx *ctx, 
	flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);



	mtu = flow->tuplehash[dir].tuple.mtu + ctx->offset;

	if (unlikely(nf_flow_exceeds_mtu(skb, mtu)))

	if (unlikely(nf_flow_exceeds_mtu(skb, mtu))) {

		flow_offload_teardown(flow);

		return 0;

	}



	ip6h = (struct ipv6hdr *)(skb_network_header(skb) + ctx->offset);

	thoff = sizeof(*ip6h) + ctx->offset;